The present invention relates to a pick device intended for the shuttle of a weaving machine and comprising an accumulator for a working medium, for example hydraulic oil, which can be filled into and emptied out of the accumulator. A pick-executing unit is also incorporated, which performs its pick-executing as a result of the emptying of the working medium out of the accumulator.
In weaving machines it is previously known to use hydraulically operating pick devices, with which the shuttles of the weaving machine are thrown or pushed through the warp between their positions in the shuttle boxes. The known pick devices comprise an accumulator which can be charged with hydraulic oil by means of a hydraulic pump, which is connected to the accumulator via a nonreturn valve. The hydraulic oil is pumped into the accumulator by means of the hydraulic pump, whose executed pump pressure determines the pick force.
The shuttles push through the warp, and between both sides of the fabric, weft threads of varying quality and size, which creates different resistances for the shuttles. Moreover, weave patterns depending on the number of threads on the race plate give different resistances for the shuttles.
This means that the known pick device must be dimensioned so as to provide sufficient impact for the shuttle or shuttles connected to the thread or threads giving the greatest resistance. The shuttle concerned must be given a speed which allows the shuttle to reliably reach the catch side at the same time as which the weaving process can be carried through at an optimum rate.
The abovementioned means that a shuttle or shuttles with low resistance to their weft threads reach the catch side at speeds which can result in problems and, for example, cause rebounding at the catch side and, thus, stoppage of the weaving machine during ongoing weaving. Shuttles and shuttle boxes may also be subjected to undue mechanical effects, wear, and the like.